DESCRIPTION (provided by investigator): Within the developmental psychopathology literature there is an increasing awareness that childhood and adolescent disorders, like their adult counterparts, are characterized to a large degree by disturbances in emotional processes. Despite this awareness and the substantial research base on normative emotional development and socialization, however, there has been very little research examining emotional processes in clinical samples of children and adolescents. This gap is perhaps most notable in the case of unipolar depressive disorder where the prominence of affective symptomatology has led numerous researchers and theorists to define it as a disorder of emotion. A key task awaiting attention is the delineation of the emotional processes characteristic of unipolar depressive disorder, as well as the identification of both continuities and discontinuities with normative developmental functioning (NIH, PA-00-105, 2000). The current application is aimed at addressing these limitations by proposing the following aims: 1) To delineate the aspects of emotional functioning that are disrupted in unipolar affective disorder by conducting a between-group analysis comparing dimensions of emotion functioning (e.g., frequency, intensity, duration; using a multi-method assessment of the key domains of emotional output (behavior, experience, & physiology;), and focusing on dysregulation of negative and positive emotional states; 2) To examine and identify family processes that serve to influence the level of adolescent emotion dysregulation displayed; and 3) To test a hypothesized mediational model whereby emotional dysregulation mediates the relation between family processes and adolescent depression.